A good book on LF exposure, reciprocity and bellows extension exposure compensation

[Timmyjoe]

Been stuck inside, so spending some time experimenting with my view camera. I am looking for a resource, maybe a good book, that covers, in detail, the issues of film reciprocity for long exposures, and the exposure compensation required when using long bellows extensions.

Thought maybe Ansel's book "The Camera" would cover this but not so much, and then I thought "View Camera Technique" would cover it, but looking thru the table of contents, I don't see it listed.

Can anyone recommend a good book that covers these two issues as they pertain to Large Format photography and the view camera?

Thanks in advance for any input.

Best,
-Tim

[Dan Fromm]

Can anyone recommend a good book that covers these two issues as they pertain to Large Format photography and the view camera?

Exposure has to be adjusted for reciprocity failure and for magnification for all sizes of camera. In these respects LF is nothing special. Any good book on macro/closeup photography will explain how to adjust exposure for magnification. Film information sheets give film-specific information on exposure compensation for very long and short exposures.

The first post in this https://www.largeformatphotography.i...mainly)-lenses discussion has a link to a list of sources of all sorts of useful information. It also has an annotated list of books on cluseup/macro.

[Wheathins]

Been stuck inside, so spending some time experimenting with my view camera. I am looking for a resource, maybe a good book, that covers, in detail, the issues of film reciprocity for long exposures, and the exposure compensation required when using long bellows extensions.

Thought maybe Ansel's book "The Camera" would cover this but not so much, and then I thought "View Camera Technique" would cover it, but looking thru the table of contents, I don't see it listed.

Can anyone recommend a good book that covers these two issues as they pertain to Large Format photography and the view camera?

Thanks in advance for any input.

Best,
-Tim

It's pretty simple to calculate yourself. Since f stop is a ratio of the lens focal length to the diameter of the lens pupil. Think of macro shots as using a longer focal length lens. So just calculate the pupil size for whatever aperture you want to shoot at. Then measure the bellows extension, and use those to numbers to calculate you effective f stop. Then use that effective f stop yo calculate exposure.

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[Dan Fromm]

It's pretty simple to calculate yourself. Since f stop is a ratio of the lens focal length to the diameter of the lens pupil. Think of macro shots as using a longer focal length lens. So just calculate the pupil size for whatever aperture you want to shoot at. Then measure the bellows extension, and use those to numbers to calculate you effective f stop. Then use that effective f stop yo calculate exposure.

There's more to it than that. See the Lefkowitz book mentioned in the link.

[r.e.]

I am looking for a resource ... that covers, in detail, ... the exposure compensation required when using long bellows extensions.

If you don't mind using simple math, forum participant and former moderator Ken Lee has a good page on his website: https://kennethleegallery.com/html/tech/bellows.php

My personal view is that a lot of the allegedly simple, workaround methods are more trouble than they are worth. The forum home page article on computing bellows compensation was prepared 24 years ago. At one point, the article says "[This method] requires no fancy gadgets to purchase nor algebraic formulae to memorize." A few things have happened since 1998, such as almost everyone having a smartphone in their pocket with a calculator app. If you want to understand what's going on behind the math, you'll find it useful to read about the inverse square law.

[r.e.]

I am looking for a resource ... that covers, in detail, the issues of film reciprocity...

I'll just comment on the nuts and bolts of the computation. The available information depends on what film you're talking about.

Kodak's data sheet for Portra 160 and Portra 400 tells you nothing about how to compute reciprocity failure. It tells you to "experiment". Many people use an app called Reciprocity Timer, about which there are discussions on this and other photography forums.

Ilford, on the other hand, does give guidance on computing reciprocity failure for its films: Ilford Film Reciprocity Failure Compensation. For Ilford, you can use Reciprocity Timer or do the math. The math is dead simple, and I imagine that every smartphone calculator has the necessary x^y function. I've just finished making an exposure worksheet. Ilford's formula, for HP4+ and HP5+, is in the last box of the worksheet, which is attached to post #8 in this current thread: https://www.largeformatphotography.i...sure-Worksheet

If you read Ilford's data sheet on reciprocity failure, note the caveats to the calculations.